1. Field of the Invention
This invention relates to a printing apparatus to be suitably used for a system for printing images by means of a printer connected thereto by way of an interface conforming to the IEEE (the Institute of Electrical and Electronics Engineers) 1394 Standards.
2. Related Background Art
The IEEE 1394 Standards defines various physical and electric standards for connectors with which various devices are provided for interconnection. It is possible to automatically selected the mode of transmitting and receiving digital data at high speed by automatically connecting devices in the selected mode such as Hot Plug and Play as devices provided with interfaces conforming to the IEEE 1394 standards are physically connected. For such reasons, the IEEE 1394 Standards are currently popularly used as standards for serial interfaces of the industry at large.
In recent years, there have been proposed techniques for using a printer and printing still images received by means of an STB (set top box) or a digital television receiving set by way of a network.
When there is a printing job and it is necessary to cause a printing apparatus designed for such a purpose and an STB for controlling the printing operation of such a printing apparatus to carry out the job, a command packet (JOB_QUEUE) containing a control job command including additional job information (add_job) about the added job is sent to the printing apparatus. Upon receiving the command, the printing apparatus is shifted from initial state (job_exist) M101 to receive wait state (receiving_active) M102 of standing by for receiving the printing data as shown in FIG. 1 of the accompanying drawings.
In the receive wait state M102, the printing apparatus is ready for receiving not only a command packet (CAPTURE) containing a transmit data command including receive request information (receive) but also a command packet (OPERATION_MODE) containing a control printing setup command requiring alternation of the current printing setup.
In the receive wait state M102, the printing apparatus returns to the initial state M101 when it receives a command packet (JOB_QUEUE) containing a control job command including job cancellation information (cancel_job), whereas, it temporarily moves to print wait state M103 and moves further to print state M104 after the elapse of a predetermined period of time when a command packed containing a control job command including job closing information (close_job). As a result, the printing apparatus carriers out the specified printing operation, using the printing data received by means of the transmit data command and also the printing conditions set up by the control printing setup command. When the printing operation is completed or a command packet containing a job control command including job cancellation information, the printing apparatus returns to the initial state M101.
However, with a printing apparatus having such states to take in a manner as described above, if a control printing setup command is input while the apparatus is receiving printing data according to the data transmission command in the receive wait state M102, the conditions set up for printing can be modified to give rise to problems while the apparatus is actually printing.
In view of the above pointed out circumstances, it is therefore the object of the present invention to provide a printing apparatus, a printing control device and a printing system that can stably carry out a printing operation without giving rise to such a problem.
According to the invention, the above object is achieved by providing a printing apparatus comprising:
a printing engine adapted to printing, using printing data;
a data interface for receiving printing data contained in a packet conforming to the IEEE 1394 Standards from outside and outputting a response packet in response to the command packet conforming to the IEEE 1394 Standards received by it from outside; and
a controller for controlling the operation mode of said printing engine and/or said data interface;
said controller controlling said data interface so as to make it operate in a command receive mode for receiving a command packet upon receiving an add printing command;
said controller controlling said data interface so as to make it operate in a command limit mode for limiting the reception of command packets other than the one containing said transmit data command upon receiving a transmit data command for receiving printing data.
In another aspect of the invention, there is provided a printing method comprising:
a step of receiving printing data contained in a packet conforming to the IEEE 1394 Standards from outside;
a step of outputting a response packet in response to the command packet conforming to the IEEE 1394 Standards received by it from outside; and
a step of controlling the operation mode of the printing control section for controlling the printing operation using printing data and/or the operation mode of the input/output section;
said controlling step being adapted to controlling said input/output section so as to make it operate in a command packet reception mode of receiving command packets upon receiving an add printing command from outside and limiting the reception of command packets other than the one containing said transmit data command upon receiving a transmit data command for receiving printing data.
In still another aspect of the invention, there is provided a printing control device comprising:
an image processor for generating printing data for printing operations;
a data interface for outputting a command for controlling the operation mode of a printing apparatus for carrying out a printing operation by using printing data generated by said image processor, said command being contained in a packet conforming to the IEEE 1394 Standards; and
a controller for monitoring the operation mode of said printing apparatus and generating a command to be output to said printing apparatus from said data interface;
said controller controlling said processing apparatus so as to operate in a command receive mode for receiving commands by outputting an add printing command for making said printing apparatus carry out a printing operation from said data interface and in a command limit mode for limiting the reception of command packets other than the one containing said transmit data command by outputting a transmit data command for receiving input data from said data interface.
In still another aspect of the invention, there is provided a printing control method adapted to:
generating a printing data to be used for a printing operation;
outputting a command for controlling the operation mode of a printing apparatus for carrying out a printing operation using said generated printing data, said command being contained in a packet conforming to the IEEE (the Institute of Electrical and Electronics Engineers) 1394 Standards; and
controlling said printing apparatus so as to output an add printing command to said printing apparatus in order to making said printing apparatus carry out a printing operation and bring said printing apparatus into a command limiting mode for limiting the reception of command packets other than the one containing a data transmission command by outputting said data transmission command for receiving a printing data to said printing apparatus.
In still in another aspect of the invention, there is provided a printing system comprising:
a printing control device including:
an image processing means for generating printing data to be used for printing;
a first input/output means adapted to outputting a command for controlling the operation mode of the printing apparatus for printing, using the printing data generated by said image processing means, said command being contained in a packet conforming to the IEEE (the Institute of Electrical and Electronics Engineers) 1394 Standards; and
a first controller for monitoring the operation of said printing apparatus and generating the command to be output from said input/output means to said printing apparatus; and
a printing apparatus including:
a printing means for printing, using the printing data from said printing control device;
a second input means adapted to inputting printing data contained in a packet conforming to the IEEE 1394 Standards and outputting a response packed in response to said command packet conforming to the the IEEE 1394 Standards from said printing control device; and
a second controller for controlling the operation mode or said printing means and/or said second input/output means;
said first controller being adapted to controlling said second input/output means so as to make it operate in a command receive mode for outputting an add printing command for making said printing apparatus carry out a printing operation from said first input/output means to said second input/output and receiving a command packet and in a command limit mode for outputting a transmit data command for receiving printing data from said first input/output means to said printing apparatus and limiting the reception of command packets other than the one containing said transmit data command.
As described above, according to the invention, it is now possible to control the operation mode so as to use a command receive mode for receiving a command packet when making the printing apparatus carrying out a printing operation and a command limit mode for limiting the reception of command packets other than the one containing a transmit data command when a transmit data command is input for printing data so that no processing operation for other commands will be conducted while transmitting data and the ongoing printing operation can be carried out on a reliable basis.